Patent Document 1 discloses an extruder that allows a screw to feed wood-based biomass chips introduced into a cylinder while subjecting the biomass chips to steam heating.
Patent Document 2 discloses a screw extruder that introduces wood chips into a cylinder and feeds the chips with water added thereto and that shears the chips under pressure and heat and pushes the sheared chips out of the cylinder so that the chips are subjected to bulking to decompose lignin.
Patent Document 3 discloses a double-screw extruder with a double screw including a kneading disc inside a heating barrel with a heater.
Patent Document 1: JP Patent Publication (Kokai) No. 2007-202518A
Patent Document 2: JP Patent Publication (Kokai) No. 4-146281A
Patent Document 3: JP Patent Publication (Kokai) No. 2004-58271A